Phosphate in RODI and Red Sea Blue Bucket

[medusala]

Hi all,

I have phosphorus levels of 35 ppb (0.1 ppm phosphate) in freshly mixed saltwater, measured with Hanna Phosphorus ULR Checker. Help me out.

RODI filter: Aquatic Life RO Buddie Four Stage Reverse Osmosis System

I've been using it for three months and just tested it. Phosphorus came out to 8-12 ppb (0.25 to 0.37 ppm).

I contacted Aquatic Life to see what the phosphorus levels are supposed to be at with this filter.

Anyone else have experience with this filter?

I'm thinking of getting another RODI filter. Any suggestions on best price for absolutely no phosphates or other issues?


Salt Mix: Red Sea Blue Bucket

Can anyone direct me to threads measuring the parameters in all the various salt mixes? I've seen some on here but can't find them at the moment. My bucket doesn't have the MyBatch information available.

My RODI water is at 8-12 ppb, but then after mixing salt, it goes up to 35 ppb. So I am thinking some must be coming from the salt mix.

Anyone else have issues with phosphates in Red Sea Blue Bucket?


Thanks in advance!

 

[Randy Holmes-Farley]

It is likely time to replace the DI resin.

Have you measured the TDS of the output?

 

[medusala]

The DI resin can be exhausted in 3 months?

I have not tested TDS. I'll look into getting a meter.

 

[medusala]

And any TDS meters you would recommend?

 

[Thor2j]

The DI resin can be exhausted in 3 months?

I have not tested TDS. I'll look into getting a meter.

Very easily. Depends on tds into the resin.

 

[Randy Holmes-Farley]

And especially the CO2 level in the water, and the total water run through.

IMO, brand of TDS meter is not critical as exact accuracy is not needed.

 

[Randy Holmes-Farley]

I discuss TDS and TDS meters here:

What is TDS? by Randy Holmes-Farley - Reefkeeping.com
http://www.reefkeeping.com/issues/2004-04/rhf/feature/index.htm

and RO/DI systems here:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-05/rhf/index.htm

 

[medusala]

Awesome thanks for the info!

 

[Randy Holmes-Farley]

You're welcome.

Happy Reefing.

 

[griff500]

Not wishing to hijack the thread, but I have found that my RO water ends up with about 0.2 phosphate measured with the Hanna ULR meter and it is going through two DI pods and shows 0 TDS. I changed everything except the membrane, which had been changed a few months prior, and got the same reading.

Any thoughts?

 

[skim]

Not wishing to hijack the thread, but I have found that my RO water ends up with about 0.2 phosphate measured with the Hanna ULR meter and it is going through two DI pods and shows 0 TDS. I changed everything except the membrane, which had been changed a few months prior, and got the same reading.

Any thoughts?

You can not use the Hanna to test fresh water it can only test salt water as per Hanna. You will get false readings.

 

[griff500]

You can not use the Hanna to test fresh water it can only test salt water as per Hanna. You will get false readings.

I have read that and also the opposite. The reading was the same once salt was added, so that would go against your statement.

 

[skim]

Not really, many times Phos is present in freshly made Salt water and after some time of mixing only to just disappear. It's not my statement that is direct from Hanna, like posted as per Hanna. It has something to do with the reagent.

 

[griff500]

Not really, many times Phos is present in freshly made Salt water and after some time of mixing only to just disappear. It's not my statement that is direct from Hanna, like posted as per Hanna. It has something to do with the reagent.

So you are saying that Hanna can give a false reading even in saltwater if it has been recently mixed? I've never seen anything to say that saltwater should be allowed to rest for a certain period of time before testing.

I understand Hanna say this but I've heard the opposite and I'm fairly certain that I read it as a quote from Hanna somewhere.

 

[skim]

Well there have be a few posts on this very subject and I think you will find they just repeat what I just posted. Yes I am saying you can get false readings on freshly made water, as it has not been mixed thoroughly. If you are looking for a 100% answer go to the Hanna site and contact them or better yet call them. The other thing is maybe your TDS meters are off and your DI resign is or has crapped out and you need some new resign.

 

[skim]

It is also quite common for some salts to have small traces of phos. so yes you may have Phos in your Red Sea Salt and it would be one I would say could have, as it is dried in the open air so the chances of impurities making into the final product then say a Synthetic Salt mix.

 

[griff500]

Regarding DI resins, I did say that the reading was identical after replacing both DI pods (and the other pods).

The measurement was taken in the saltwater when it had been thoroughly mixed and matched the reading from the RO. Quite a coincidence.

The TDS meter has always shown about the same reading going in and still does, so I don't think there's an issue with it. I also don't have particularly high TDS going in and so zero coming out isn't anything that I shouldn't expect.

I'm not arguing against what you said - just stating the facts of the readings from my RO and saltwater. Too much phosphate in my display, checked RO and saltwater before adding to the tank and found it there as well in equal quantities.

 

[griff500]

It is also quite common for some salts to have small traces of phos. so yes you may have Phos in your Red Sea Salt and it would be one I would say could have, as it is dried in the open air so the chances of impurities making into the final product then say a Synthetic Salt mix.

http://www.ultimatereef.net/forums/...-ULR-with-Hanna-checker&p=7238137#post7238137

Someone contacting Hanna tech support and being told the opposite.

Their website says 'ideal for saltwater aquariums' - note 'ideal', rather than 'only'. It then goes on to say it's not for cold water aquariums - note 'cold water' rather than 'fresh water'. I find the wording odd, but these days it could be just poor use of English or deliberately vague. Perhaps accuracy isn't anything to do with fresh or salt water and more related to temperature, with the photometer being calibrated for a certain anticipated temperature range. Not that I have any idea what temperature a fresh water tank would be - presumably room temperature...

I'm not sure it's particularly important as it's a rather small amount from the water change when added to the aquarium and thus diluted. I was just interested in why it might be there at all with zero TDS water. You seem to be saying that it either isn't in the RO and I'm getting a false reading or it is there but the reading isn't accurate, regardless of the RO and saltwater readings being identical, which is presumably just a coincidence...

I use Tropic Marin Pro Reef salt - not Red Sea - it's a thread hijack. ;-)

 

[Randy Holmes-Farley]

Not wishing to hijack the thread, but I have found that my RO water ends up with about 0.2 phosphate measured with the Hanna ULR meter and it is going through two DI pods and shows 0 TDS. I changed everything except the membrane, which had been changed a few months prior, and got the same reading.

Any thoughts?

Might be a testing error, or might be real. Is there a lot of phosphate in the raw tap water?

 

[griff500]

Might be a testing error, or might be real. Is there a lot of phosphate in the raw tap water?

I haven't tested the tap water - I'll give that a go out of curiosity.

I have tested multiple times and been using the Hanna for quite some time with the same method. Lack of consistency in results is large when it is there and I usually put it down to bad reagents, which isn't exactly unheard of from Hanna. A repeated test usually gets the expected result.